[U-Boot] [PATCH v2 02/20] i2c: Add TPS6586X driver
Simon Glass
sjg at chromium.org
Fri Jan 13 22:35:17 CET 2012
This power management chip supports battery charging and a large number
of power supplies. This initial driver only provides the ability to adjust
the two synchronous buck converters SM0 and SM1 in a stepwise manner.
Signed-off-by: Simon Glass <sjg at chromium.org>
---
Changes in v2:
- Split PMU code into separate TPS6586X driver
drivers/power/Makefile | 1 +
drivers/power/tps6586x.c | 293 ++++++++++++++++++++++++++++++++++++++++++++++
include/tps6586x.h | 68 +++++++++++
3 files changed, 362 insertions(+), 0 deletions(-)
create mode 100644 drivers/power/tps6586x.c
create mode 100644 include/tps6586x.h
diff --git a/drivers/power/Makefile b/drivers/power/Makefile
index ead00f8..9db8ea2 100644
--- a/drivers/power/Makefile
+++ b/drivers/power/Makefile
@@ -28,6 +28,7 @@ LIB := $(obj)libpower.o
COBJS-$(CONFIG_FTPMU010_POWER) += ftpmu010.o
COBJS-$(CONFIG_TWL4030_POWER) += twl4030.o
COBJS-$(CONFIG_TWL6030_POWER) += twl6030.o
+COBJS-$(CONFIG_TPS6586X_POWER) += tps6586x.o
COBJS := $(COBJS-y)
SRCS := $(COBJS:.o=.c)
diff --git a/drivers/power/tps6586x.c b/drivers/power/tps6586x.c
new file mode 100644
index 0000000..5915d6f
--- /dev/null
+++ b/drivers/power/tps6586x.c
@@ -0,0 +1,293 @@
+/*
+ * Copyright (c) 2011 The Chromium OS Authors.
+ * (C) Copyright 2010,2011 NVIDIA Corporation <www.nvidia.com>
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+#include <common.h>
+#include <tps6586x.h>
+#include <asm/io.h>
+#include <i2c.h>
+
+/*
+ * abs() handles unsigned ints, shorts and chars and returns a signed long.
+ * TODO: Move this into common?
+ */
+#define abs(x) ({ \
+ long ret; \
+ { \
+ typeof((x)) __x = (x); \
+ ret = (__x < 0) ? -__x : __x; \
+ } \
+ ret; \
+ })
+
+static int bus_num; /* I2C bus we are on */
+#define I2C_ADDRESS 0x34 /* chip requires this address */
+static char inited; /* 1 if we have been inited */
+
+enum {
+ /* Registers that we access */
+ SUPPLY_CONTROL1 = 0x20,
+ SUPPLY_CONTROL2,
+ SM1_VOLTAGE_V1 = 0x23,
+ SM1_VOLTAGE_V2,
+ SM0_VOLTAGE_V1 = 0x26,
+ SM0_VOLTAGE_V2,
+ PFM_MODE = 0x47,
+
+ /* Bits in the supply control registers */
+ CTRL_SM1_RAMP = 0x01,
+ CTRL_SM1_SUPPLY2 = 0x02,
+ CTRL_SM0_RAMP = 0x04,
+ CTRL_SM0_SUPPLY2 = 0x08,
+};
+
+#define MAX_I2C_RETRY 3
+int tps6586x_read(int reg)
+{
+ int i;
+ uchar data;
+ int retval = -1;
+ int old_bus_num;
+
+ old_bus_num = i2c_get_bus_num();
+ i2c_set_bus_num(bus_num);
+
+ for (i = 0; i < MAX_I2C_RETRY; ++i) {
+ if (!i2c_read(I2C_ADDRESS, reg, 1, &data, 1)) {
+ retval = (int)data;
+ goto exit;
+ }
+
+ /* i2c access failed, retry */
+ udelay(100);
+ }
+
+exit:
+ i2c_set_bus_num(old_bus_num);
+ debug("pmu_read %x=%x\n", reg, retval);
+ if (retval < 0)
+ debug("%s: failed to read register %#x: %d\n", __func__, reg,
+ retval);
+ return retval;
+}
+
+int tps6586x_write(int reg, uchar *data, uint len)
+{
+ int i;
+ int retval = -1;
+ int old_bus_num;
+
+ old_bus_num = i2c_get_bus_num();
+ i2c_set_bus_num(bus_num);
+
+ for (i = 0; i < MAX_I2C_RETRY; ++i) {
+ if (!i2c_write(I2C_ADDRESS, reg, 1, data, len)) {
+ retval = 0;
+ goto exit;
+ }
+
+ /* i2c access failed, retry */
+ udelay(100);
+ }
+
+exit:
+ i2c_set_bus_num(old_bus_num);
+ debug("pmu_write %x=%x: ", reg, retval);
+ for (i = 0; i < len; i++)
+ debug("%x ", data[i]);
+ if (retval)
+ debug("%s: failed to write register %#x\n", __func__, reg);
+ return retval;
+}
+
+/*
+ * Get current voltage of SM0 and SM1
+ *
+ * @param sm0 Place to put SM0 voltage
+ * @param sm1 Place to put SM1 voltage
+ * @return 0 if ok, -1 on error
+ */
+static int read_voltages(int *sm0, int *sm1)
+{
+ int ctrl1, ctrl2;
+ int is_v2;
+
+ /*
+ * Each vdd has two supply sources, ie, v1 and v2.
+ * The supply control reg1 and reg2 determine the current selection.
+ */
+ ctrl1 = tps6586x_read(SUPPLY_CONTROL1);
+ ctrl2 = tps6586x_read(SUPPLY_CONTROL2);
+ if (ctrl1 == -1 || ctrl2 == -1)
+ return -1;
+
+ /* Figure out whether V1 or V2 is selected */
+ is_v2 = (ctrl1 | ctrl2) & CTRL_SM0_SUPPLY2;
+ *sm0 = tps6586x_read(is_v2 ? SM0_VOLTAGE_V2 : SM0_VOLTAGE_V1);
+ *sm1 = tps6586x_read(is_v2 ? SM1_VOLTAGE_V2 : SM1_VOLTAGE_V1);
+ if (*sm0 == -1 || *sm1 == -1)
+ return -1;
+
+ return 0;
+}
+
+static int set_voltage(int reg, int data, int rate)
+{
+ uchar control_bit;
+ uchar buff[3];
+
+ control_bit = (reg == SM0_VOLTAGE_V1 ? CTRL_SM0_RAMP : CTRL_SM1_RAMP);
+
+ /*
+ * Only one supply is needed in u-boot. set both v1 and v2 to
+ * same value.
+ *
+ * When both v1 and v2 are set to same value, we just need to set
+ * control1 reg to trigger the supply selection.
+ */
+ buff[0] = buff[1] = (uchar)data;
+ buff[2] = rate;
+
+ /* write v1, v2 and rate, then trigger */
+ if (tps6586x_write(reg, buff, 3) ||
+ tps6586x_write(SUPPLY_CONTROL1, &control_bit, 1))
+ return -1;
+
+ return 0;
+}
+
+static int calculate_next_voltage(int voltage, int target, int step)
+{
+ int diff = voltage < target ? step : -step;
+
+ if (abs(target - voltage) > step)
+ voltage += diff;
+ else
+ voltage = target;
+
+ return voltage;
+}
+
+int tps6586x_set_pwm_mode(int mask)
+{
+ uchar val;
+ int ret;
+
+ assert(inited);
+ ret = tps6586x_read(PFM_MODE);
+ if (ret != -1) {
+ val = (uchar)ret;
+ val |= mask;
+
+ ret = tps6586x_write(PFM_MODE, &val, 1);
+ }
+
+ if (ret == -1)
+ debug("%s: Failed to read/write PWM mode reg\n", __func__);
+
+ return ret;
+}
+
+int tps6586x_adjust_sm0_sm1(int sm0_target, int sm1_target, int step, int rate,
+ int min_sm0_over_sm1)
+{
+ int sm0, sm1;
+ int bad;
+
+ assert(inited);
+
+ /* get current voltage settings */
+ if (read_voltages(&sm0, &sm1)) {
+ debug("%s: Cannot read voltage settings\n", __func__);
+ return -1;
+ }
+
+ /*
+ * if vdd_core < vdd_cpu + rel
+ * skip
+ *
+ * This condition may happen when system reboots due to kernel crash.
+ */
+ if (min_sm0_over_sm1 != -1 && sm0 < sm1 + min_sm0_over_sm1) {
+ debug("%s: SM0 is %d, SM1 is %d, but min_sm0_over_sm1 is %d\n",
+ __func__, sm0, sm1, min_sm0_over_sm1);
+ return -1;
+ }
+
+ /*
+ * Since vdd_core and vdd_cpu may both stand at either greater or less
+ * than their nominal voltage, the adjustment may go either directions.
+ *
+ * Make sure vdd_core is always higher than vdd_cpu with certain margin.
+ * So, find out which vdd to adjust first in each step.
+ *
+ * case 1: both sm0 and sm1 need to move up
+ * adjust sm0 before sm1
+ *
+ * case 2: both sm0 and sm1 need to move down
+ * adjust sm1 before sm0
+ *
+ * case 3: sm0 moves down and sm1 moves up
+ * adjusting either one first is fine.
+ *
+ * Adjust vdd_core and vdd_cpu one step at a time until they reach
+ * their nominal values.
+ */
+ bad = 0;
+ while (!bad && (sm0 != sm0_target || sm1 != sm1_target)) {
+ int adjust_sm0_late = 0; /* flag to adjust vdd_core later */
+
+ debug("%d-%d %d-%d ", sm0, sm0_target, sm1, sm1_target);
+
+ if (sm0 != sm0_target) {
+ /*
+ * if case 1 and case 3, set new sm0 first.
+ * otherwise, hold down until new sm1 is set.
+ */
+ sm0 = calculate_next_voltage(sm0, sm0_target, step);
+ if (sm1 < sm1_target)
+ bad |= set_voltage(SM0_VOLTAGE_V1, sm0, rate);
+ else
+ adjust_sm0_late = 1;
+ }
+
+ if (sm1 != sm1_target) {
+ sm1 = calculate_next_voltage(sm1, sm1_target, step);
+ bad |= set_voltage(SM1_VOLTAGE_V1, sm1, rate);
+ }
+
+ if (adjust_sm0_late)
+ bad |= set_voltage(SM0_VOLTAGE_V1, sm0, rate);
+ debug("%d\n", adjust_sm0_late);
+ }
+ debug("%d-%d %d-%d done\n", sm0, sm0_target, sm1, sm1_target);
+
+ return bad ? -1 : 0;
+}
+
+int tps6586x_init(int bus)
+{
+ bus_num = bus;
+ inited = 1;
+
+ return 0;
+}
diff --git a/include/tps6586x.h b/include/tps6586x.h
new file mode 100644
index 0000000..ab88082
--- /dev/null
+++ b/include/tps6586x.h
@@ -0,0 +1,68 @@
+/*
+ * (C) Copyright 2010,2011
+ * NVIDIA Corporation <www.nvidia.com>
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+#ifndef __H_
+#define _TPS6586X_H_
+
+enum {
+ /* SM0-2 PWM/PFM Mode Selection */
+ TPS6586X_PWM_SM0 = 1 << 0,
+ TPS6586X_PWM_SM1 = 1 << 1,
+ TPS6586X_PWM_SM2 = 1 << 2,
+};
+
+/**
+ * Enable PWM mode for selected SM0-2
+ *
+ * @param mask Mask of synchronous converter to enable (TPS6586X_PWM_...)
+ * @return 0 if ok, -1 on error
+ */
+int tps6586x_set_pwm_mode(int mask);
+
+/**
+ * Adjust SM0 and SM1 voltages to the given targets in incremental steps.
+ *
+ * @param sm0_target Target voltage for SM0 in 25mW units, 0=725mV, 31=1.5V
+ * @param sm1_target Target voltage for SM1 in 25mW units, 0=725mV, 31=1.5V
+ * @param step Amount to change voltage in each step, in 25mW units
+ * @param rate Slew ratein mV/us: 0=instantly, 1=0.11, 2=0.22,
+ * 3=0.44, 4=0.88, 5=1.76, 6=3.52, 7=7.04
+ * @param min_sm0_over_sm1 Minimum amount by which sm0 must exceed sm1.
+ * If this condition is not met, no adjustment will be
+ * done and an error will be reported. Use -1 to skip
+ * this check.
+ * @return 0 if ok, -1 on error
+ */
+int tps6586x_adjust_sm0_sm1(int sm0_target, int sm1_target, int step, int rate,
+ int min_sm0_over_sm1);
+
+/**
+ * Set up the TPS6586X I2C bus number. This will be used for all operations
+ * on the device. This function must be called before using other functions.
+ *
+ * @param bus I2C bus number containing the TPS6586X chip
+ * @return 0 (always succeeds)
+ */
+int tps6586x_init(int bus);
+
+#endif /* _TPS6586X_H_ */
--
1.7.7.3
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